1. Field of the Invention
This invention relates to a high voltage device having a Schottky diode, and to a high voltage device having a Schottky diode integrated with a metal-oxide-semiconductor (MOS) transistor.
2. Description of the Prior Art
Power devices are required to be fast switching and sustainable to high voltage of hundreds Volts (V). Therefore high voltage (HV) devices such as HV metal-oxide-semiconductor (HVMOS) transistor, insulated gate bipolar transistor (IGBT), and Schottky diode which have high-speed switching characteristics have been developed and commonly used for power conversion, power control, and so forth of the power system in instruments such as home appliances, communication devices and control devices of in-vehicle motor.
Among those HV devices, Schottky diode's voltage drop at a forward bias of about 1 mA is in the rage of 0.15 V to 0.45 V, while the conventional silicon diode is of about 0.6 V. Therefore Schottky diode is more preferable in voltage-clamping applications and in applications for preventing transistor saturation.